title: RBC transfusions among hemodialysis patients (1999-2010): influence of hemoglobin concentrations below 10 g/dL.
abstract: BACKGROUND
  Changes in anemia management over the past decade have produced downward shifts in hemoglobin concentrations. We aimed to examine the effect on use of red blood cell (RBC) transfusions.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  We identified point prevalent Medicare hemodialysis patients as of January 1 of each year (1999-2010) and categorized them based on 3-month (April to June) mean hemoglobin levels (<10 or ≥10 g/dL) in each year.
  
  
  METHODS
  Hemoglobin patterns over time and clinical profiles based on achieved hemoglobin concentrations.
  
  
  RESULTS
  RBC transfusion use.
  
  
  METHODS
  We used negative binomial modeling to examine the effect of hemoglobin level <10 g/dL on transfusion use, adjusting for case-mix differences.
  
  
  RESULTS
  Proportions of patients with mean hemoglobin levels <10 g/dL decreased from 10% (1999) to ~4% (2005), but began increasing after 2006 and reached 6% by 2010. Accounting for case-mix differences, transfusion rates remained relatively constant at approximately 7.9 per 100 person-months for patients with hemoglobin levels <10 g/dL and 2 per 100 person-months for patients with hemoglobin levels ≥10 g/dL. Patients with average hemoglobin levels <10 g/dL were more likely to receive transfusions (risk ratio, 2.2; 95% CI, 2.1-2.2) even after adjustment; the risk ratio doubled if hemoglobin levels remained <10 g/dL for 6 months (4.4; 95% CI, 3.7-5.2).
  
  
  CONCLUSIONS
  Limited in generalizability to patients with Medicare as primary payer; residual confounding from factors such as frailty and chronic inflammation cannot be excluded; categorizing patients based on an average of 3 outpatient hemoglobin measurements may introduce some misclassification.
  
  
  CONCLUSIONS
  Risk of transfusion increases substantially with hemoglobin concentrations <10 g/dL; risk appears to be independent of other clinical factors. If anemia management patterns shift toward lower hemoglobin concentrations, RBC transfusion use likely will increase in dialysis patients.
authors.affiliation: Chronic Disease Research Group, Minneapolis Medical Research Foundation, Minneapolis, MN. Electronic address: dgilbertson@cdrg.org.
authors.forename: David T
authors.initials: DT
authors.lastname: Gilbertson
authors.forename: Keri L
authors.initials: KL
authors.lastname: Monda
authors.forename: Brian D
authors.initials: BD
authors.lastname: Bradbury
authors.forename: Allan J
authors.initials: AJ
authors.lastname: Collins
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000628:therapy*; D015331:Cohort Studies; D019468:Disease Management; D017707:Erythrocyte Transfusion; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D008297:Male; D006278:Medicare; D008875:Middle Aged; D006435:Renal Dialysis / Q000009:adverse effects*; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000628:therapy*; D012189:Retrospective Studies; D018570:Risk Assessment; D016896:Treatment Outcome; D014481:United States
chemical_list: D006454:Hemoglobins
keywords: Hemodialysis; hemoglobin concentration; red blood cell transfusion